Movement mechanism

ABSTRACT

A movement mechanism comprises a substantially spherical holder and a substantially bowl-shaped ring, which, when inserted into each other, are rotatable relative to each other about at least one first axis (A), which lies in a plane which is substantially parallel with the top face of the holder. Driving means are provided for enabling movement of the holder relative to the ring. These driving means comprise a non-straight driving rod bearing-mounted in the holder and means for activating the driving rod. The driving rod is further connected with a driving part, which is rotatably mounted in a recess in the ring relative to a second axis (B), which second axis (B) lies in a plane equal or parallel to the top face of the ring, and which second axis (B) lies at an angle of approximately 90° to the first axis (A).

BACKGROUND

The present invention relates to a movement mechanism, comprising asubstantially spherical holder and a substantially bowl-shaped ring,which, when inserted into each other, are rotatable relative to eachother about at least one first axis, which lies in a plane which issubstantially parallel with the top face of the holder, while drivingmeans are provided for enabling movement of the holder relative to thering, which driving means comprise a non-straight driving rodbearing-mounted in the holder, as well as means for activating thedriving rod.

Such a movement mechanism can, for instance, be used for causing anobject fixedly connected to the holder to make a movement about one ortwo axes relative to the fixedly arranged bowl-shaped ring, and can beused for, for instance, wing mirrors of vehicles, in which a mirrorplate can be mounted on the bowl-shaped ring, while the holder ismounted in the housing of the mirror plate, which housing can be fixedon a vehicle. Since the driving means for the mirror plate can be fittedin the holder, a rather compact construction of the mirror-adjustingmeans can be obtained, which; in view of the increasingly stringentrequirements imposed on the dimensions of such mirror-adjusting means,is of great importance.

A movement mechanism as described above is known for a movement abouttwo axes from International Patent Application PCT/NL00/00326, whichcomprises a dish located between a holder and a bowl, which is onlyrotatably connected with the holder about a first axis, and which isonly rotatably connected with the holder about a second axis. Here, thedriving means comprise a driving rod for each of the rotationpossibilities about the first and the second axis, respectively. Thisdriving rod is provided with a projection which is moveable in andthrough a slot in the holder, and which engages in a second slotprovided in the bowl, which is perpendicular to the slot in the holder.Between this projection and therefore also the driving rod, on the onehand, and the slots in the holder and the bowl, on the other hand, toomuch play not avoidable in practice appears, as a result of which theaccuracy of this drive does not meet the highest requirements.

SUMMARY

The invention has for its object to prevent this drawback and to realizea relative movement of a spherical holder relative to a bowl-shaped ringabout at least one axis, while the compact construction of the movementmechanism is maintained and can even be further improved in specialembodiments.

To this end, according to the invention the movement mechanism ischaracterized in that the driving rod is connected with a driving part,which is rotatably mounted in a recess in the ring relative to a secondaxis, which second axis lies in a plane equal or parallel to the topface of the ring, and which second axis lies at an angle ofapproximately 90° to the first axis.

In a special embodiment the driving rod has the shape of a ring segment,which is rotatable about a third axis (C), which lies in a plane equalor parallel to the top face of the holder, and which lies at an angle ofapproximately 45° to the first (A). This embodiment is particularlyimportant for reasons of space saving.

The above special embodiment, however, is connected with a problem. Thethird axis (C) lies substantially at an angle of 45° to the second axis(B). When the ring segment rotates relative to this third axis (C), thedriving part will not be able to make a pure rotating movement in therecess in the ring. To solve this problem, different possibilities havebeen found.

In a first embodiment according to invention the recess in the ring hasthe shape of a slotted hole and the driving part has the shape of acylinder, while the length of the slotted hole is substantially orientedin a direction parallel to that of the first axis (A).

In a second embodiment the driving part is movably connected with thedriving rod in such a manner that, when the driving rod rotates, arelatively small displacement of the driving part in substantially adirection parallel to that of the first axis (A) becomes possible.

In a third embodiment the bowl-shaped ring has a recess, which ismovably arranged in the ring in such a manner that, when the driving rodrotates, a relatively small displacement of the recess in substantiallya direction parallel to that of the first axis (A) becomes possible.

Although in all of the three above embodiments the driving rod ispreferably provided with a toothing and in all of these cases thedriving rod can carry out a rotation movement, which is defined relativeto an axis which substantially coincides with the third axis (C), thisselection of the driving rod is a condition for a fourth embodiment.Here, the means for activating the driving rod are further formed by adriving system provided with a driven toothed wheel. A fourth solutionof the above problem is obtained when the driving system is slidable ina direction which is substantially parallel to that of the third axis(C). Here, the driven toothed wheel will be provided with a shaft part,which is radially bearing-mounted in a groove in the driving rod.

To enable a movement of the holder relative to the ring about twosubstantially mutually perpendicular axes, the driving means areprovided with a second non-straight driving rod, which is connected withan associated driving part, which is rotatably mounted in a secondrecess in the ring relative to the first axis (A), while the relevantdriving rods are arranged in the holder substantially parallel to eachother. Exactly by arranging the driving rods parallel to each other, anadditional space is obtained in the holder for the associated motorswith transmission means.

The invention not only relates to a movement mechanism, but also to awing mirror for a vehicle provided with such a movement mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in more detail with reference to theaccompanying drawing. In this drawing:

FIG. 1 is a perspective view of the movement mechanism according to theinvention;

FIG. 2 is a top plan view of the movement mechanism in FIG. 1;

FIG. 3 is a side view of this movement mechanism according to the arrowsP;

FIG. 4 shows an exemplary embodiment of the driving means for themovement mechanism;

FIGS. 5A–5C show, seen from different angles, an embodiment of thedriving rod with the driving parts;

FIGS. 6A–6D show, seen from different angles, another embodiment of thedriving rod with the driving parts; and

FIGS. 7A–7E show, seen from different angles, a further embodiment ofthe driving rod with the driving part.

Corresponding parts in these figures are indicated by equal referencenumerals.

DETAILED DESCRIPTION

The movement mechanism according to FIGS. 1–3 is shown for a movement ofa substantially spherical holder 1 relative to a substantiallybowl-shaped ring 2 about a first axis A, which lies in a plane which issubstantially parallel with the top face of the holder 1. The cardanicsuspension of the holder and the ring are not shown any further, becausethis is not important for the description of the invention. The drivingmeans provided for enabling movement of the holder 1 relative to thering comprise a non-straight driving rod 3 bearing-mounted in the holder1 as well as means for activating the driving rod 3. The driving rod 3has the shape of a ring segment rotatable relative to an axis C. Thisaxis C lies at an angle of 45° to the axis A. The ring segment isprovided with teeth mashing with the teeth of a driven toothed wheel 6of a driving system 9 shown (see FIG. 4). This driving system 9comprises a motor and associated transmission means; these componentsare not shown, however, for simplicity's sake. By actuating the steppingmotor the toothed wheel 6 is driven through the transmission means,which has the result that the ring segment is displaced in the holder.Through the connection of the driving rod 3 with a driving part 4 whichis rotatably mounted in a recess 5 in the ring 2 relative to an axis Bperpendicular to the axis A, a displacement of the driving rod 3 in theholder means that the driving part 4 displaces the ring 2 relative tothe holder 1. The driving part 4 is designed as a cylindrical element.

If the driving rod 3 was arranged in such a manner that it could berotated about the axis A, then the recess 5 could be circular, and ifthe holder and the ring rotated relative to each other about the axis B,then the driving part 4 could make a rotating movement about its axiscoinciding with the axis B. For this situation the driving rod 3 and thedriving part 4 are shown in FIGS. 5A–5C. In the embodiment of FIGS. 1–3the driving rod 3, however, can only move parallel to a planeperpendicular to the axis C. During this movement the driving part 4 ismoved somewhat laterally while taking the ring 2 along. In theembodiment shown this is rendered possible by giving the recess 5 theshape of a slotted hole. For this situation the driving rod 3 and thedriving part 4 are shown in FIGS. 6A–6D. The reason for which thedriving rod 3 is movable parallel to a plane perpendicular to the axis Cresides in the fact that the movement mechanism described herein will beused in practice for a movement of the holder relative to the ring abouttwo axes, namely A and B, and that for a rotation about one of the twoaxes it is favorable to actuate both motors provided for the purpose.For a movement mechanism of another type this uses is already describedin the above International Patent Application PCT/NL00/00326. Here, thedriving mechanism 3 is arranged on the side of the partition 10.Diametrically relative to a plane extending parallel to this partitionthrough the center of the movement mechanism a partition 11 is providedparallel to the partition 10. For a two-axis movement of the holder 1relative to the ring 2 a second driving rod is arranged on the side ofthis partition, that is to say in the same way as the driving rod 3 isarranged on the side of the partition 10. Of course, the driving meansrequired therefor are arranged in the holder. In that case thearrangement of the two driving rods gives an additional space savingcompared to the situation in which the two driving rods areperpendicular to each other, as is the case in the above internationalpatent application. Because the movements about the two axes A and B areotherwise realized in a similar manner, in the embodiment depicted themovement mechanism is only shown for a movement about the axis A.

In another embodiment the recess is kept circular indeed, but thedriving part 4 is somewhat movably connected with the driving rod 3.This situation is shown in FIGS. 7A–7E, of which FIG. 7A is a magnifiedview of a detail in FIG. 7B. Here, the driving part 4 is connected withthe driving rod through an elastic element 12.

In yet another embodiment, as shown in FIG. 4, the recess 5 is also keptcircular. A laterally directed movement of the driving part 4 occurringduring the displacement of the driving rod 3 is prevented by providingthe toothed wheel 6 with a shaft part 7 which is radiallybearing-mounted in a groove 8 in the driving rod 3. During thedisplacement of the driving rod 3 a slight axial movement is possiblebetween the shaft part 7 and the groove 8.

The invention is not limited to the exemplary embodiments describedherein with reference to the drawing, but comprises all kinds ofmodifications thereof, of course as far as falling with the scope ofprotection of the appended claims. Thus, for instance, it is possible tomake up the laterally directed movement of the driving part 4 occurringduring a displacement of the driving rod 3 by providing the recess 5 ina plate piece which is laterally displaceable relative to the ring 2. Itis further possible to provide a crown toothing, instead of the toothingshown in FIG. 4, on the surface 13 of the driving rod 3. The drivingsystem 9 can then be arranged in a position rotated through 90°.

1. A movement mechanism, comprising a substantially spherical holder (1) and a substantially bowl-shaped ring (2), which, when inserted into each other, are rotatable relative to each other about at least one first axis (A), which lies in a plane which is substantially parallel with the top face of the holder (1), while driving means are provided for enabling movement of the holder (1) relative to the ring (2), which driving means comprise a non-straight driving rod (3) bearing-mounted in the holder (1), as well as means (6, 9) for activating the driving rod (3), characterized in that the driving rod (3) has the shape of a ring segment and is connected with a driving part (4), which is rotatably mounted in a recess (5) in the ring (2) relative to a second axis (B), which second axis (B) lies in a plane equal or parallel to the top face of the ring (2), and which second axis (B) lies at an angle of approximately 90° to the first axis (A), wherein the ring segment is rotatable about a third axis (C) which lies in a plane equal or parallel to the top face of the holder (1) and which lies at an angle of approximately 45° to the first axis (A).
 2. A wing mirror for a vehicle, provided with a movement mechanism according to claim
 1. 3. A movement mechanism according to claim 1 characterized in that the recess (5) has the shape of a slotted hole and the driving part (4) has the shape of a cylinder, while the length of the slotted hole is substantially oriented in a direction parallel to that of the first axis (A).
 4. A movement mechanism according to claim 1, characterized in that the driving part (4) is movably connected with the driving rod (3) in such a manner that, when the driving rod (3) rotates, a relatively small displacement of the driving part (4) in substantially a direction parallel to that of the first axis (a) becomes possible.
 5. A movement mechanism according to claim 1, characterized in that the ring is provided with a recess (5), which is movably arranged in the ring (2) in such a manner that, when the driving rod (3) rotates, a relatively small displacement of the recess in substantially a direction parallel to that of the first axis (A) becomes possible.
 6. A movement mechanism according to claim 1, characterized in that the driving rod (3) is provided with a toothing and can carry out a rotation movement, which is defined relative to an axis which substantially coincides with the third axis (C).
 7. A movement mechanism according to claim 6, characterized in that the means for activating the driving rod (3) are formed by the driving system (9) provided with a driven toothed wheel (6).
 8. A movement mechanism according to claim 7, characterized in that the driving system (9) is slidable in a direction which is substantially parallel to that of the third axis (C).
 9. A movement mechanism according to claim 7, characterized in that the driven toothed wheel (6) is provided with a shaft part (7), which is radially bearing-mounted in a groove (8) in the driving rod (3).
 10. A movement mechanism according to claim 1, characterized in that, to enable a movement of the holder relative to the ring about two substantially mutually perpendicular axes, the driving means are provided with a second non-straight driving rod, which is connected with an associated driving part, which is rotatably mounted in a second recess in the ring relative to the first axis (A), while the relevant driving rods are arranged in the holder substantially parallel to each other. 